KR20040077279A - Apparatus for transmitting/receiving preamble in ultra wide band communication system and method thereof - Google Patents

Abstract

PURPOSE: A preamble transmitter and receiver of a UWB(Ultra Wide Band) communication system and a transmitting and receiving method thereof are provided to apply an aperiodic sequence and a periodic sequence according to characteristics by dividing a preamble of a physical layer into a synchronous preamble and a channel estimation preamble. CONSTITUTION: A preamble transmitter of a UWB communication system includes a first preamble generator, a second preamble generator, and a transmitter. The first preamble generator(1300) is used for generating the first preamble as a synchronous preamble by using an aperiodic sequence having an aperiodic correlation characteristic. The second preamble generator(1310) is used for generating the second preamble as a channel estimation preamble by using the aperiodic sequence. The transmitter is used for multiplexing the first and the preambles and transmitting the multiplexed preambles as a preamble of the UWB communication system.

Description

Apparatus and method for preamble transmission and reception in an ultra-wideband communication system {APPARATUS FOR TRANSMITTING / RECEIVING PREAMBLE IN ULTRA WIDE BAND COMMUNICATION SYSTEM AND METHOD THEREOF}

The present invention relates to an ultra-wideband communication system, and more particularly, to an apparatus and method for generating a preamble by separating a preamble for synchronization acquisition and a channel estimation.

In general, an ultra wide band (UWB) communication system is a short-range wireless communication system, which is a wireless communication system that is discussed in the Institute of Electrical and Electronics Engineers (IEEE) 802.15.3a standard specification. The ultra-wideband communication system is a technology for short-range high-speed wireless communication within a short range, for example, within 10 m, and will be described with reference to FIG. 1.

1 is a diagram schematically illustrating a piconet of a general ultra wideband communication system.

Prior to the description of FIG. 1, the ultra-wideband communication system targets short-range wireless communication due to its radio communication characteristics, and therefore, it is expected to be applied to a home network or a radar. The ultra-wideband communication system uses a piconet as a basic unit of wireless communication.

Referring to FIG. 1, first, the piconet 100 includes a piconet coordinator (PNC) 100, a plurality of devices, that is, a first device 120, a second device 130, and a first device. It consists of three devices 140 and a fourth device 150. The piconet regulator 110 transmits a beacon to the first device 120, the second device 130, the third device 140, and the fourth device 150. The operation of the device 120, the second device 130, the third device 140, and the fourth device 150 is controlled. Here, the beacon is a kind of control signal generated by the piconet regulator 110, the first device 120, the second device 130, the third device 140, The fourth device 150 adjusts its operation according to the beacon. In addition, the piconet regulator 110 may transmit data to the first device 120, the second device 130, the third device 140, and the fourth device 150. In addition, data may be transmitted between each of the first device 120, the second device 130, the third device 140, and the fourth device 150. In addition, the first device 120, the second device 130, the third device 140, and the fourth device 150 represent all devices capable of performing wireless communication. And devices such as modems, VTRs, automobiles, and the like. The piconet 100 as shown in FIG. 1 may be formed between the devices capable of wireless communication, and the piconet adjuster 110 performs overall operation control of the piconet 100.

In addition, the ultra-wideband communication system is a system for transmitting a relatively large amount of data at high speed using a relatively wide frequency band at a relatively low power in the short-range. The capacity of the ultra-wideband communication system is proportional to the bandwidth and the signal to noise ratio (SNR). The ultra-wideband communication system uses a spreading characteristic of a signal, that is, when a pulse having a very short period in the time domain is transmitted, the pulse signal is spread very widely in the frequency domain. As a result, the system makes it possible to spread the pulse trains having very short periods so that the period of the pulses can be made very short and lower than the transmission energy density per frequency, which is the basis of propagation of the noise. Broadband communication system. In the ultra-wideband communication system, the transmission frequency band is determined according to the waveform of the pulse. Due to the frequency characteristics, the ultra-wideband frequency is wider in the spreading band, so it is more resistant to fading in places with many obstacles, and has a lower power consumption since the transmission energy density per frequency is lower than that of noise.

On the other hand, in general, the wireless communication system can operate only when the synchronization between the transmitter and the receiver is exactly matched. Since the ultra wideband communication system is also a wireless communication system, the synchronization between the transmitter and the receiver must be exactly matched. In general, in order to synchronize synchronization between the transmitter and the receiver, a preamble sequence is used in a physical layer frame. There are two physical layer frame structures of the ultra-wideband communication system, namely, a first frame applied when the transmission rate is 22 Mb / s, when 33 Mb / s, when 44 Mb / s, and when 55 Mb / s. Structure and a second frame structure applied when the transmission rate is 11 Mb / s. Next, a first frame structure applied to the case where the transmission rate is 22 Mb / s, 33 Mb / s, 44 Mb / s, and 55 Mb / s will be described with reference to FIG. 2.

FIG. 2 schematically illustrates a physical layer frame structure of an ultra-wideband communication system applied when a transmission rate is 22Mb / s, 33Mb / s, 44Mb / s, and 55Mb / s. to be.

Referring to FIG. 2, first, the physical layer frame of the ultra wideband communication system applied when the transmission rate is 22Mb / s, 33Mb / s, 44Mb / s and 55Mb / s is preamble. 200, a physical (PHY: physical, hereinafter referred to as "PHY") header 210, and a media access control (MAC: hereinafter referred to as "MAC") header ( 220, a header check sequence (HCS: Header Check Sequence, hereinafter referred to as "HCS") 230, and a data + frame check sequence (FSC: Frame Check Sequence, hereinafter referred to as "FCS") ( 240, stub bits (hereinafter referred to as "SB") 250, and tail symbols (TS) (hereinafter referred to as "TS") 260. do. The preamble 200 is a quadrature phase shift keying (QPSK) symbol having a length of 160. The preamble 200 is used for acquisition of transmission and reception periods, recovery of offset of a carrier, and equalization of a received signal. The PHY header 210 has a length of 2 octets and is used to indicate information about a scrambling code, a transmission rate of a MAC frame, a data length, and the like. Here, one octet means 8 bits in length. The MAC header 220 has a length of 10 octets, a frame adjustment signal, a piconet identifier (PNID: PNID), and a destination ID (DestID). ), Source identifier (SrcID: Source IDentifier, hereinafter referred to as "SrcID"), fragmentation control (hereinafter referred to as "fragmentation control") information, and stream index ) Is used to represent information. The HCS 230 is two octets long and is used for error detection of the PHY header 210 and the MAC header 220. In the data + FCS 240, the data has a length of 0 to 2048 octets, and is used for transmitting information to be transmitted and encrypted information. In this case, the data may have any length of 0 to 2048 octets, thus enabling flexible size information and cryptographic information transmission. In addition, in the data + FCS 240, the FCS is four octets long and is used to detect errors in the transmitted data. When the size of the data + FCS 240 is not an integer multiple of the symbol size applied to the transmission rate to be transmitted, the SB 250 converts the size of the data + FCS 240 to the symbol size applied to the transmission rate. It is a kind of dummy bits inserted to generate an integer multiple. Of course, when the size of the data + FCS 240 is an integer multiple of the symbol size applied to the transmission rate to be transmitted, the SB 250 need not be inserted, the transmission rate is actually 11Mb / s in the ultra-wideband communication system In this case, the SB 250 is not inserted into the physical layer frame. This will be described in detail with reference to FIG. 3, and thus a detailed description thereof will be omitted. The TS 260 is used to indicate the initial state of the trellis.

In FIG. 2, the physical layer frame structure of the ultra-wideband communication system applied when the transmission rate is 22Mb / s, 33Mb / s, 44Mb / s and 55Mb / s has been described. Referring to FIG. 3, the physical layer frame structure of the ultra-wideband communication system applied when the transmission rate is 11Mb / s will be described.

3 is a diagram schematically illustrating a physical layer frame structure of an ultra-wideband communication system applied when a transmission rate is 11 Mb / s.

Referring to FIG. 3, first, the physical layer frame of the ultra wideband communication system applied when the transmission rate is 11 Mb / s includes a preamble 300, a PHY header + MAC header + HCS 310, a PHY header + MAC. Header + HCS 320 and data + FCS 330 and TS 340. The physical layer frame structure of the ultra-wideband communication system applied to the case where the transmission rate described in FIG. 2 is 22Mb / s, 33Mb / s, 44Mb / s and 55Mb / s, and FIG. The physical layer frame structure of the ultra-wideband communication system applied when the transmission rate shown in Fig. 11 has a similar structure, but the physical layer frame of the ultra-wideband communication system applied when the transmission rate is 11Mb / s. The PHY header, MAC header, and HCS are repeated once more to minimize the error rate of the header part. The repeatedly inserted PHY header + MAC header + HCS 320 is treated like the same block together with the data + FCS 330 and TS 340 and modulated and demodulated. As shown in FIG. 2, when the transmission rate is 11 Mb / s, the SB may be separately inserted because the size of the data + FCS 330 becomes an integer multiple of the speed to be transmitted, that is, the symbol size applied to 11 Mb / s. There is no need, and therefore the SB is not inserted into a physical layer frame when the transmission rate is 11Mb / s.

Next, a physical layer frame transmission apparatus of an ultra-wideband communication system applied to a case where a transmission rate is 22 Mb / s, 33 Mb / s, 44 Mb / s, and 55 Mb / s will be described with reference to FIG. 4. Let's do it. For convenience of description, only the physical layer frame transmission apparatus of the ultra-wideband communication system to be applied when the transmission rate is 22Mb / s, 33Mb / s, 44Mb / s and 55Mb / s It should be noted that

4 is a diagram schematically illustrating an internal structure of a physical layer frame transmitter for transmitting the physical layer frame of FIG. 2.

Referring to FIG. 4, when data 400 to be transmitted is first transmitted, the data 400 is input to the PHY header generator 405, the MAC header generator 410, and the data + FCS generator 415. The PHY header generator 405 generates a PHY header corresponding to the input data 400, that is, a PHY header including information on a scrambling code, a transmission rate and a data length of a MAC frame, and then multiplexer (MUX). 420 and the multiplexer 445. The MAC header generator 410 generates a MAC header including a MAC header, that is, a frame adjustment signal, a PNID, a DestID, a SrcID, fragmentation control information, and stream index information corresponding to the input data 400. After the output to the multiplexer 420 and the multiplexer 435. The data + FCS generator 415 generates data + FCS corresponding to the input data 400 and outputs the data + FCS to the multiplexer 435. Here, the data + FCS generator 415 inserts and outputs the generated data and the FCS corresponding to the data, which is a 32-bit cyclic redundancy check (CRC).

The multiplexer 420 multiplexes the signals output from the PHY header generator 405 and the MAC header generator 410 according to the physical layer frame structure described with reference to FIG. 2 and then outputs the signals to the HCS generator 430. . The HCS generator 430 generates an HCS corresponding to a signal output from the multiplexer 420, that is, a PHY header and a MAC header, and then outputs the HCS to the multiplexer 435. The multiplexer 435 multiplexes the signals output from the MAC header generator 410 and the data + FCS generator 415 according to the physical layer frame structure described with reference to FIG. 2 and then to a scrambler 440. Output The scrambler 440 inputs the signal output from the multiplexer 435, scrambles the scrambling code with a preset scrambling code, and outputs the scrambler 445 to the multiplexer 445. The multiplexer 445 multiplexes the signal output from the PHY header generator 405 and the signal output from the scrambler 440 according to the physical layer frame structure described with reference to FIG. 2 and then multiplexer 455. Will output

The preamble generator 425 generates a preamble and outputs the preamble to the multiplexer 455. The SB generator 450 transmits the data because the size of the data + FCS is not an integer multiple of the symbol size applied to the transmission rate. To generate an integer multiple of the symbol size applied to the speed SB is generated and output to the multiplexer 455. The multiplexer 455 inputs the signal output from the preamble generator 425, the signal output from the multiplexer 445, and the signal output from the SB generator 450 to input the physical layer described with reference to FIG. 2. Multiplexed according to the frame structure and output to the multiplexer (465). In addition, the TS generator 460 generates a TS to indicate the trellis initial state and outputs the TS to the multiplexer 465. The multiplexer 465 multiplexes the signal output from the multiplexer 455 and the signal output from the TS generator 460 according to the physical layer frame structure described with reference to FIG. 2 and then airs through an antenna. Send on air.

4 illustrates a physical layer frame generation apparatus of an ultra-wideband communication system applied to a case where a transmission rate is 22Mb / s, 33Mb / s, 44Mb / s, and 55Mb / s. The physical layer frame receiving apparatus of the ultra-wideband communication system applied when the transmission rate is 22Mb / s, 33Mb / s, 44Mb / s and 55Mb / s will be described with reference to FIG. Shall be.

FIG. 5 is a diagram schematically illustrating an internal structure of a physical layer frame receiving apparatus corresponding to the physical layer frame transmitting apparatus of FIG. 4.

Referring to FIG. 5, when a signal is first received through an antenna, the received signal is input to a demultiplexer (DEMUX) 500. The demultiplexer 500 demultiplexes the received signal corresponding to the physical layer frame structure described with reference to FIG. 2 and outputs the demultiplexer 505 and the preamble checker 510. Here, the demultiplexer 500 demultiplexes the received signal corresponding to the physical layer frame structure described in FIG. 2, that is, the preamble and the remaining fields, that is, the PHY header, the MAC header, the HCS, and the data +. The preamble is output to the preamble checker 510 and demultiplexed to the FCS, SB and TS, and the remaining fields are output to the demultiplexer 505. Here, for convenience of description, the SB and TS are not directly related to the present invention among the remaining fields except for the preamble in the physical layer frame, and thus detailed description thereof will be omitted. The preamble checker 510 inputs a preamble output from the demultiplexer 500, acquires synchronization with the transmitter using the input preamble, and performs channel estimation.

Meanwhile, the demultiplexer 505 inputs the signal output from the demultiplexer 500 and demultiplexes the demultiplexer 515 and the PHY header corresponding to the physical layer frame structure described with reference to FIG. 2. Output to analyzer 525. Here, the demultiplexer 505 outputs a PHY header among the remaining fields from which the preamble is removed to the PHY header analyzer 525, and outputs the remaining fields to the descrambler 515. The PHY header analyzer 525 analyzes the PHY header output from the demultiplexer 505, extracts information on the transmission rate, data length, and the like of the scrambling code and the MAC frame, and outputs the information to the data decompressor 540. The descrambler 515 inputs the signal output from the demultiplexer 505, descrambles the same scrambling code as the scrambling code applied by the physical layer transmitter, and outputs the descrambler 520 to the demultiplexer 520. The demultiplexer 520 inputs the signal output from the descrambler 515 and demultiplexes the signal according to the physical layer frame structure described in FIG. 2 so that the MAC header is the MAC header analyzer 530, and the HCS is a header error. To the detector 535, data + FCS is output to the data decompressor 540.

The MAC header analyzer 530 inputs the MAC header output from the demultiplexer 520 to extract the frame adjustment signal, the PNID, the DestID, the SrcID, the fragmentation control information, and the stream index information to restore the data. Output to the machine 540. The header error detector 535 inputs the HCS output from the demultiplexer 520, detects whether the PHY header and the MAC header have errors, and then outputs the result of the PHY header analyzer 525 and the MAC header analyzer. Output to (530). When the header error detector 535 determines that an error occurs in the PHY header and the MAC header, the header error detector 535 no longer performs the physical layer frame processing. The data restorer 540 restores the data output from the demultiplexer 520 using the information output from the PHY header analyzer 525 and the information output from the MAC header analyzer 530. Here, the demultiplexer 520 outputs data + FCS, and the data decompressor 540 determines whether an error occurs with the FCS, and if it is determined that the data is free of errors, the demultiplexer 520 outputs data + FCS. To perform a restore operation. In this way, the data 545 restored by the data decompressor 540 becomes the data transmitted from the transmitter.

Next, the structure of the preamble generator 425 in the physical layer frame transmitting apparatus described with reference to FIG. 4 will be described with reference to FIG. 6.

FIG. 6 is a diagram illustrating the structure of a preamble generator in detail in the physical layer frame transmitting apparatus of FIG. 4.

6, the physical layer frame transmitter shown in FIG. 6 is the same apparatus as the physical layer frame transmitter described with reference to FIG. 4 except that the structure of the preamble generator 425 described with reference to FIG. It only differs in that it is disclosed. In addition, in order to describe only the preamble in detail, the signals other than the preamble in the physical layer frame, that is, the PHY header, the MAC header, the HCS, the data + FCS, and the SB and TS are defined as "physical data". Let's do it. Referring to FIG. 6, first, a constant amplitude zero auto correlation (CAZAC) sequence generator 600 generates a CAZAC sequence having a length of 16 and outputs the same to a repeater 620 and a -1 multiplier 630. Here, the preamble has a length of 160 symbols in a physical layer frame applied to the ultra wideband communication system when its transmission rate is 22Mb / s, 33Mb / s, 44Mb / s and 55Mb / s. Since the CAZAC sequence of length 16 generated by the CAZAC sequence generator 600 must be repeated, the CAZAC sequence of length 16 generated by the CAZAC sequence generator 600 is output to the repeater 620. In addition, the guitar signal 610 excluding the preamble is input to the multiplexer 650.

The iterator 620 repeats the CAZAC sequence of length 16 output from the CAZAC sequence generator 600 nine times and outputs the same to the multiplexer 640. In addition, the -1 multiplier 630 multiplies the CAZAC sequence of length 16 output from the CAZAC sequence generator 600 by -1 and outputs the result to the multiplexer 640. The multiplexer 640 multiplexes the CAZAC sequence of length 144 output from the iterator 620 and the CAZAC sequence of length 16 multiplied by -1 output from the -1 multiplier 630 and multiplexer 650. Will output Here, the multiplexer 640 adds a preamble signal by adding a CAZAC sequence of length 16 multiplied by -1 output from the first multiplier 630 consecutively to the CAZAC sequence of length 144 output from the repeater 620. Create The reason why the -1 multiplier 630 multiplies the CAZAC sequence of length 16 output from the CAZAC sequence generator 600 by -1 is to indicate that the preamble is terminated by the CAZAC sequence multiplied by the symbol. The multiplexer 650 multiplexes the signal output from the multiplexer 640 and the guitar signal 610 in the physical layer frame 660 according to the physical layer frame structure described with reference to FIG. 2.

Next, the preamble structure output from the multiplexer 640 of FIG. 6 will be described with reference to FIG. 7.

FIG. 7 is a diagram schematically illustrating a preamble structure in a physical layer frame of a general UWB communication system. Referring to FIG.

Referring to FIG. 7, as described with reference to FIG. 6, the UWB communication system uses a CAZAC sequence as a preamble. When the CAZAC sequence of length 16 output from the AZAC signal generator 600 of FIG. 6 is referred to as P0, the P0 is repeated nine times in the repeater 620. In FIG. 7, the P0 is repeated nine times to generate P0 to P8. The CAZAC sequence obtained by multiplying P0 by -1 in the -1 multiplier 630 of FIG. 6 is referred to as E. As described with reference to FIG. 6, E indicates that the preamble is terminated. That is, the P0 to P8 and E are sequentially concatenated to generate one preamble, and the P0 to P8 and E are sequentially concatenated to perform synchronization acquisition and channel estimation.

Next, elements of the CAZAC sequence will be described with reference to FIG. 8.

8 is a table illustrating element values of a CAZAC sequence having a general length of 16. Referring to FIG.

Referring to FIG. 8, first, a CAZAC sequence represents a sequence having a constant value of constant size of all elements and having a zero autocorrelation characteristic. Here, the zero autocorrelation characteristic is a characteristic in which autocorrelation has a value of a product of a sequence value and a magnitude value of the elements when synchronization is consistent, and autocorrelation is zero when synchronization is not identical. Indicates. The CAZAC sequence has an advantage of having excellent correlation characteristics and good characteristics for channel estimation, but has a disadvantage in that the sequence size is limited according to a modulation scheme. For example, the length of the binary phase shift keying (BPSK) modulation scheme is 2 ² (= 4), the length of the length of the BPSK modulation scheme is 2 ⁴ (= 16), and the length of the 8PSK modulation scheme. The sequence size is limited to 2 ⁸ (= 256) depending on the modulation scheme.

In general, a wireless communication system performs synchronization acquisition and channel estimation of a transmission / reception period using a preamble, and identifies a start of a frame. It is currently proposed to use a CAZAC sequence of length 16 as a preamble in an ultra-wideband wireless communication system. However, when the QPSK scheme is used as the modulation scheme, hardware implementations of the transmitter and the receiver of the ultra-wideband communication system are difficult, and the complexity thereof is increased when the actual transmitter and receiver are implemented in hardware. Therefore, in the ultra-wideband communication system, a scheme of using a BPSK scheme instead of the QPSK scheme is considered as a modulation scheme. When the BPSK scheme is used as the modulation scheme, hardware implementation of a transmitter and a receiver is facilitated, but a limitation in sequence length occurs due to the characteristics of the CAZAC sequence. That is, when the BPSK scheme is used as the modulation scheme as described above, the length of the CAZAC sequence is limited to four. The CAZAC sequence has excellent correlation characteristics due to its sequence characteristics and excellent channel estimation. However, when the BPSK scheme is used as a modulation scheme, it is difficult to obtain synchronization because the CAZAC sequence has a short sequence length.

Here, the reason why it is difficult to acquire synchronization when the CAZAC sequence having a length of 4 is applied as a preamble is as follows.

When a preamble having a length of 160 is generated by repeating a CAZAC sequence having a length of 4, even if the actual synchronization matches in the process of acquiring synchronization using the preamble, the correlation value obtained when the actual synchronization does not match It does not have a relatively large difference compared to the degree value. Thus, it is difficult to accurately determine when motives coincide, and thus obtaining motives is also difficult. Therefore, there is a need for a new preamble for acquiring synchronization without using the length 4 CAZAC sequence as a preamble.

Accordingly, an object of the present invention is to provide an apparatus and method for generating a preamble in an ultra wideband communication system.

Another object of the present invention is to provide an apparatus and method for separately generating a synchronization acquisition preamble and a channel estimation preamble in an ultra-wideband communication system.

It is still another object of the present invention to provide an apparatus and method for generating a preamble using an aperiodic sequence or a periodic sequence according to the purpose in an ultra-wideband communication system.

A transmission apparatus according to a first embodiment of the present invention for achieving the above objects; A preamble transmission apparatus of an ultra-wideband communication system, comprising: a first preamble generator for generating a first preamble, which is a preamble for synchronization acquisition, using an aperiodic sequence having an aperiodic correlation characteristic, and for channel estimation using the aperiodic sequence And a second preamble generator for generating a second preamble, which is a preamble, and a transmitter for multiplexing the first preamble and the second preamble and transmitting the multiple preambles to the preamble of the ultra wideband communication system.

A transmission apparatus according to a second embodiment of the present invention for achieving the above objects; A preamble transmission apparatus of an ultra-wideband communication system, comprising: a first preamble generator for generating a first preamble as a preamble for synchronization acquisition using an aperiodic sequence having aperiodic correlation characteristics, and a periodic sequence having a periodic correlation characteristic And a second preamble generator for generating a second preamble, which is a channel estimation preamble, and a transmitter for multiplexing the first preamble and the second preamble and transmitting the multiplexes to the preamble of the ultra wideband communication system.

The transmission method according to the first embodiment of the present invention for achieving the above objects; A method of transmitting a preamble in an ultra-wideband communication system, the method comprising: generating a first preamble, which is a preamble for synchronization acquisition, using an aperiodic sequence having aperiodic correlation characteristics; and a preamble for channel estimation using the aperiodic sequence. Generating a second preamble and multiplexing the first preamble and the second preamble and transmitting the multiple preambles to the preamble of the ultra wideband communication system.

A transmission method according to a second embodiment of the present invention for achieving the above objects; A method of transmitting a preamble in an ultra-wideband communication system, the method comprising: generating a first preamble, which is a preamble for synchronization acquisition, using an aperiodic sequence having an aperiodic correlation characteristic, and for estimating a channel using a periodic sequence having a periodic correlation characteristic Generating a second preamble, which is a preamble, and transmitting the preamble of the ultra wideband communication system by multiplexing the first preamble and the second preamble.

The receiving device of the present invention for achieving the above objects; A preamble receiving apparatus of an ultra-wideband communication system, comprising: a demultiplexer for demultiplexing a received signal, a first preamble serving as a synchronization acquisition preamble, a second preamble serving as a channel estimation preamble, a demultiplexer for outputting data, and a first preamble A correlation estimator for performing synchronization acquisition, outputting synchronization information according to the synchronization acquisition result, a channel estimator for performing channel estimation with the second preamble, and outputting a channel estimation value according to the channel estimation result; And a data decompressor for restoring the data to original information data with the synchronization information and the channel estimate.

The receiving method of the present invention for achieving the above objects; A method of receiving a preamble in an ultra-wideband communication system, the method comprising: demultiplexing a received signal and outputting a first preamble, which is a preamble for synchronization acquisition, a second preamble, which is a preamble for channel estimation, and data, and synchronizing with the first preamble Performing acquisition, outputting synchronization information according to the synchronization acquisition result, performing channel estimation with the second preamble, outputting a channel estimate value according to the channel estimation result, And restoring the data to the original information data with the channel estimate.

1 schematically illustrates a piconet of a typical ultra wideband communication system;

FIG. 2 is a diagram schematically illustrating a physical layer frame structure of an ultra-wideband communication system applied when a transmission rate is 22 Mb / s, 33 Mb / s, 44 Mb / s, and 55 Mb / s

3 is a diagram schematically illustrating a physical layer frame structure of an ultra-wideband communication system applied when a transmission rate is 11 Mb / s.

FIG. 4 schematically illustrates an internal structure of a physical layer frame transmitting apparatus for transmitting the physical layer frame of FIG. 2.

5 is a diagram schematically illustrating an internal structure of a physical layer frame receiving apparatus corresponding to the physical layer frame transmitting apparatus of FIG. 4.

FIG. 6 is a diagram illustrating the structure of a preamble generator in detail in the physical layer frame transmitting apparatus of FIG. 4. FIG.

7 schematically illustrates a preamble structure in a physical layer frame of a general ultra wideband communication system;

8 is a table illustrating element values of a CAZAC sequence of general length 16. FIG.

9 schematically illustrates a physical layer frame structure of an ultra-wideband communication system according to an embodiment of the present invention.

10 is a schematic diagram illustrating periodic sequence autocorrelation detection

11 schematically illustrates autocorrelation detection of an aperiodic sequence

FIG. 12 is a diagram illustrating an internal structure of an ARM sequence generation device to be applied to the first preamble 930 of FIG. 9.

FIG. 13 schematically illustrates an internal structure of a physical layer frame transmitter for transmitting the physical layer frame of FIG. 9.

14 is a flowchart illustrating a process of transmitting a physical layer frame corresponding to FIG. 13.

FIG. 15 schematically illustrates an internal structure of a physical layer frame receiving apparatus corresponding to FIG. 13.

16 is a flowchart illustrating a process of receiving a physical layer frame corresponding to FIG. 15.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

The present invention divides a preamble of an ultra wide band (UWB) communication system for synchronization acquisition and channel estimation, and is used for the preamble and channel estimation used for the synchronization acquisition. The present invention proposes a method of generating a preamble corresponding to each characteristic of the preamble. Hereinafter, for convenience of description, the preamble used for the synchronization acquisition will be referred to as a "first preamble", and the preamble used for the channel estimation will be referred to as a "second preamble". In particular, the present invention provides a first embodiment in which a first preamble is generated using an aperiodic sequence, and a second preamble is also generated using an aperiodic sequence, and a first preamble is generated using an aperiodic sequence. And the second preamble has two embodiments of the second embodiment, which are generated using a periodic sequence. In the present invention, it is assumed that an aperiodic recursive multiplex (ARM) sequence is used as the aperiodic sequence, and a constant amplitude zero autocorrelation (CAZAC) sequence is used as the periodic sequence. It will be described on the assumption that it is used, and any sequence having aperiodic characteristics other than the ARM sequence can be used as the aperiodic sequence, and any sequence having periodic characteristics other than the CAZAC sequence as the periodic sequence can be used. Of course it can be used. Accordingly, the first embodiment of the present invention generates both the first preamble and the second preamble using the ARM sequence, and the second embodiment of the present invention generates the first preamble using the ARM sequence, and the second preamble. Is generated using the CAZAC sequence.

9 is a diagram schematically illustrating a physical layer frame structure of an ultra-wideband communication system according to an embodiment of the present invention.

9, the physical layer frame may include a preamble, a physical header (PHY), and a header as described in the related art. A media access control (MAC) header, a header check sequence (HCS), and a data + frame check sequence (FSC). : Frame Check Sequence (hereinafter referred to as "FCS"), stub bits (SB: Stuff Bits, hereinafter referred to as "SB"), and tail symbols (TS: Tail Symbols, hereinafter referred to as "TS"). It will be referred to as). The above physical layer frame structure is applied when the transmission rate is 22Mb / s, when 33Mb / s, when 44Mb / s and when 55Mb / s, and when the transmission rate is 11Mb / s The preamble, PHY header + MAC header + HCS, PHY header + MAC header + are different from when the transmission rate is 22Mb / s, 33Mb / s, 44Mb / s and 55Mb / s. HCS and data + FCS and TS. Hereinafter, in describing the present invention, all signals other than the preamble in the physical layer frame structure will be referred to as "physical data".

Referring to FIG. 9, first, the physical layer frame is divided into a preamble 910 and physical data 920. In addition, the preamble 910 includes a first preamble 930 and a second preamble 940. The first preamble 930 is used for synchronization acquisition between the transmitter and the receiver, and the second preamble 940 is used for channel estimation. In the first embodiment of the present invention, both the first preamble 930 and the second preamble 940 are generated by using an aperiodic sequence having excellent autocorrelation characteristics, and according to the second embodiment of the present invention. In FIG. 3, the first preamble 930 is generated using an aperiodic sequence having excellent periodic correlation characteristics, and the second preamble 940 is generated using a periodic sequence having excellent channel estimation characteristics. As described in the above-mentioned prior art, the current ultra-wideband communication system is proposed to use a CAZAC sequence as a preamble, and to use a Quadrqture Phase Shift Keying (QPSK) scheme as a modulation scheme. When the QPSK scheme is used as the modulation scheme in the ultra-wideband communication system, hardware implementation of the transmitter and the receiver is difficult, and even when the hardware and the actual transmitter and receiver are implemented in hardware, the complexity of using the QPSK scheme is difficult. Consider using the BPSK scheme. However, when the BPSK scheme is used, the sequence length is limited to a sequence having a length of 4 due to the CAZAC sequence characteristics, and using the CAZAC sequence having a length of 4 as a preamble makes it difficult to obtain synchronization as described in the related art. Has Accordingly, in the present invention, the preamble 910 is divided into a first preamble 930 for synchronous acquisition and a second preamble 940 for channel estimation, so that the first preamble 930 is an aperiodic sequence. A sequence is generated using the sequence, and the second preamble 940 is generated using the ARM sequence or the CAZAC sequence which is a periodic sequence.

Next, the autocorrelation property of the periodic sequence will be described with reference to FIG. 10.

10 is a diagram schematically illustrating detection of a periodic sequence autocorrelation.

Before describing FIG. 10, whether the synchronization of the received signal is generally obtained may be determined using an autocorrelation function of the received signal. In the correlation for discontinuous transmission, there are two correlation calculation methods. The first method is to calculate the periodic correlation, and the second method is to calculate the aperiodic correlation. In this way, which of the two correlation calculation methods is used to calculate the autocorrelation is determined according to the characteristics of the signal for which the autocorrelation is to be obtained. FIG. 10 illustrates a method of detecting autocorrelation corresponding to the periodic correlation calculation method.

Referring to FIG. 10, first, a correlation section indicates an entire section for measuring correlation with respect to a received signal. An effective correlation section of the correlation section represents a section that substantially affects the calculation of autocorrelation between the received signals. The autocorrelation in the effective correlation section is expressed by Equation 1 below.

In Equation 1, x (t) represents a received signal, Denotes an autocorrelation function of the received signal x (t). In Equation 1, the autocorrelation function Is the average of the product of the time at time t and the value at t + τ over a sufficiently large time T, which is preset. As such, when the periodic sequence is used, the higher the autocorrelation characteristic is, the better the characteristics are.

In FIG. 10, a method of detecting autocorrelation corresponding to a periodic correlation calculation method has been described. Next, the autocorrelation property of the aperiodic sequence will be described with reference to FIG. 11.

FIG. 11 is a diagram schematically illustrating autocorrelation detection of an aperiodic sequence.

Referring to FIG. 11, first, a correlation section indicates an entire section for measuring correlation with respect to a received signal. An effective correlation section among the correlation sections indicates a section that substantially affects the calculation of autocorrelation between the received signals. Here, the effective correlation section is different from the effective correlation section of the periodic correlation calculation method described with reference to FIG. 10 because the aperiodic sequence is not continuously received. That is, in the aperiodic correlation calculation method, the received signal is considered to be a single wave, and when a delay occurs, the effective correlation interval is reduced because the delayed interval for a predetermined time is excluded from the effective correlation interval. This means that the values after the reception signal is delayed are all set to "0". When the autocorrelation is obtained by the aperiodic correlation calculation method in the effective correlation section, Equation 2 is obtained.

In Equation 2, x (t) represents a received signal, Denotes an autocorrelation function of the received signal x (t). In Equation 2, the autocorrelation function Is the average of the product of the time at time t and the value at t + τ over a sufficiently large time T, which is preset. In this way, it can be said that the aperiodic sequence has better characteristics as the autocorrelation is lower. That is, a sequence having a low autocorrelation value when the synchronization does not coincide, and a sequence having a high autocorrelation value when the synchronization is consistent, is an excellent sequence.

As described above, the biggest difference between the periodic correlation calculation method and the aperiodic correlation calculation method is that the effective correlation intervals are different in calculating autocorrelation. In other words, since the same signal is repeatedly received when the periodic sequence is used, since the effective correlation interval is continued, the same repeated signals affect the autocorrelation, but the non-periodic sequence is used. Since it is assumed that a particular signal is received only once, other signals that are continuously received after the signal do not affect autocorrelation. For example, using the CAZAC sequence 1101 having a length of 4, periodic autocorrelation and aperiodic autocorrelation are obtained as follows. Here, it is assumed that the delay time of the received signal is one symbol long.

As described above, the biggest difference between the calculation of periodic autocorrelation and aperiodic autocorrelation is whether the same signal, that is, the same sequence is repeatedly received or only received once. In general, the preamble is regarded as a signal transmitted only once, not a signal repeatedly transmitted per corresponding physical layer frame. Therefore, when the receiver does not normally receive the preamble, it is difficult to perform another operation until the next preamble is received. By using the characteristics of the preamble, the present invention will use an aperiodic sequence having an aperiodic autocorrelation rather than a periodic sequence having a periodic autocorrelation for the preamble.

On the other hand, IEEE 802.15.3a, the standard of the ultra-wideband communication system, uses a CAZAC sequence of length 16 as a preamble. However, due to a number of problems as described above, the present invention uses 128 bits of the preamble. It is proposed to use a periodic ARM sequence. In detail, the length can be increased by repeating the length 4 CAZAC sequence in order to use the length 4 CAZAC sequence for synchronization acquisition. However, if the periodic autocorrelation is obtained from the characteristics of the CAZAC sequence, synchronization is obtained. It is difficult to determine whether or not the actual synchronization has been obtained because the periodic autocorrelation is not high compared with the case where the synchronization is not obtained. That is, when the CAZAC sequence having a length of 4 is repeatedly transmitted, the autocorrelation obtained when the periodic autocorrelation is obtained is delayed by the CAZAC sequence having the length of 4 compared to the autocorrelation obtained when synchronization is obtained. The difference is as long as the length of the sequence. As a result, when the BPSK scheme is used in the ultra-wideband communication system, when the preamble is transmitted by repeating the CAZAC sequence having a length of 4, there is a difference of 4 between autocorrelations when synchronization is not obtained and synchronization is not obtained. , 4, has the disadvantage that it is difficult to actually distinguish at an energy level, and thus it may not be possible to accurately detect synchronization acquisition.

Next, an apparatus for generating an aperiodic sequence, that is, an ARM sequence, to be used for the first preamble 930 will be described with reference to FIG. 12.

FIG. 12 is a diagram illustrating an internal structure of an ARM sequence generation device to be applied to the first preamble 930 of FIG. 9.

12 is an apparatus for generating an ARM sequence of length 128 in particular, wherein first one of all possible combinations of two bits (00 or 01 or 10 or 11) of two bits is inputted as an input signal, the input signal is first input as it is. The input signal is input to the multiplexer 1200, and at the same time, the input signal is input to an exclusive logical OR (XOR) adder 1205. At the same time, the signal generator 1203 generates a signal of 01 or 10 and outputs the signal to the exclusive OR-adder 1205. The exclusive OR-adder 1205 performs an exclusive OR on the signal output from the signal generator 1203 and the input signal, and outputs the exclusive OR to the first multiplexer 1200. The first multiplexer 1200 multiplexes the input signal and the signal output from the exclusive-OR adder 1205 alternately in time to generate a 4-bit ARM sequence, and generates the 4-bit ARM sequence in a second multiplex. Output to firearm 1210 and exclusive OR adder 1215.

As such, while a 4-bit ARM sequence is input from the first multiplexer 1200 to the second multiplexer 1210, the signal generator 1213 generates a signal of 0101 or 1010 to the exclusive OR sum 1215. Output The exclusive OR adder 1215 performs an exclusive OR on the signal output from the signal generator 1213 and the 4-bit ARM sequence output from the first multiplexer 1200 and outputs the result to the second multiplexer 1210. The second multiplexer 1210 multiplexes the input signal and the signal output from the exclusive-OR sum adder 1215 alternately in time to generate an 8-bit ARM sequence, and generates the third 8-bit ARM sequence. Output to firearm 1220 and exclusive-OR adder 1225.

As such, an 8-bit ARM sequence is input from the second multiplexer 1210 to the third multiplexer 1220, and the signal generator 1223 generates a signal of 01010101 or 10101010 to the exclusive OR-adder 1225. Output The exclusive OR adder 1225 performs an exclusive OR on the signal output from the signal generator 1223 and the 8-bit ARM sequence output from the second multiplexer 1210 and outputs the result to the third multiplexer 1220. The third multiplexer 1220 generates a 16-bit ARM sequence by multiplexing the input signal and the signal output from the exclusive OR-adder 1225 alternately in time to generate a 16-bit ARM sequence, and generates the fourth multiplexed ARM sequence. Output to firearm 1230 and exclusive-OR adder 1235.

As such, while a 16-bit ARM sequence is input from the third multiplexer 1220 to the fourth multiplexer 1230, the signal generator 1233 generates a signal of 0101010101010101 or 1010101010101010 to the exclusive OR-adder 1235. Output The exclusive OR-adder 1235 performs an exclusive OR on the signal output from the signal generator 1233 and the 16-bit ARM sequence output from the third multiplexer 1220 and outputs the result to the fourth multiplexer 1230. The fourth multiplexer 1230 generates a 32-bit ARM sequence by multiplexing the input signal and the signal output from the exclusive OR-adder 1235 alternately in time, and generates a 32-bit ARM sequence by a fifth multiplex. Output to firearm 1240 and exclusive-OR adder 1245.

Thus, while the 32-bit ARM sequence is input from the fourth multiplexer 1230 to the fifth multiplexer 1240, the signal generator 1243 generates a signal of 01010101010101010101010101010101 or 10101010101010101010101010101010 to the exclusive logical sum adder 1245. Output The exclusive OR-adder 1245 performs an exclusive OR on the signal output from the signal generator 1243 and the 32-bit ARM sequence output from the fourth multiplexer 1230 and outputs the result to the fifth multiplexer 1240. The fifth multiplexer 1240 generates a 64-bit ARM sequence by multiplexing the input signal and the signal output from the exclusive OR-adder 1245 alternately in time to generate a 64-bit ARM sequence, and generates a sixth multiplexed 64-bit ARM sequence. Output to firearm 1250 and exclusive OR-adder 1255.

Thus, while the 64-bit ARM sequence is input from the fifth multiplexer 1240 to the sixth multiplexer 1250, the signal generator 1253 generates a signal of 255 by adding the logic of 255 by generating a signal of 255 by adding a signal of 0101010101010101010101010101010101 or 1010101010101010101010101010101010101010101010101010101010101010. Output The exclusive OR-adder 1255 performs an exclusive OR on the signal output from the signal generator 1253 and the 64-bit ARM sequence output from the fifth multiplexer 1240, and outputs the result to the sixth multiplexer 1250. The sixth multiplexer 1250 multiplexes the input signal and the signal output from the exclusive OR-adder 1255 in time to generate a 128-bit ARM sequence, and the generated 128-bit ARM sequence results in the It is used as the first preamble 930. 12 illustrates a case of generating a 128-bit ARM sequence as an example, an ARM sequence having a power of 2 such as 256, 512, ..., etc. may extend the structure as described with reference to FIG. Of course it can be created.

Next, a physical layer frame generation apparatus according to an embodiment of the present invention will be described with reference to FIG. 13.

FIG. 13 is a diagram schematically illustrating an internal structure of a physical layer frame transmitting apparatus for transmitting the physical layer frame of FIG. 9.

Before describing FIG. 13, the physical layer frame transmission apparatus illustrated in FIG. 13 includes signals other than the preamble in the physical layer frame, that is, a PHY header, a MAC header, and the like, in order to describe only the preamble in detail. , HCS, data + FCS, SB and TS will be defined as "physical data".

First, the first preamble generator 1300 generates an ARM sequence having a length of 128 as described with reference to FIG. 12 and outputs it to the multiplexer 1330. In addition, the second preamble generator 1310 generates an ARM sequence of length 32 or repeatedly outputs the CAZAC sequence of length 4 eight times to the multiplexer 1330. Here, in the first embodiment of the present invention, since the ARM preamble is used for the second preamble, when the first embodiment of the present invention is applied, the second preamble generator 1310 generates an ARM sequence of length 32. In contrast, in the second embodiment of the present invention, since the CAZAC sequence is used for the second preamble, when the second embodiment of the present invention is applied, the second preamble generator 1310 repeatedly generates a CAZAC sequence of length 4 eight times. Since the length of the first preamble is 128, the length of the second preamble is automatically 32. Therefore, the CAZAC sequence of length 4 is repeated eight times to be generated as the second preamble. The multiplexer 1330 includes a first preamble output from the first preamble generator 1300 and a second preamble output from the second preamble generator 1310 in a physical layer frame structure as described with reference to FIG. 9. The result is multiplexed accordingly and output to the multiplexer 1340. Meanwhile, physical data 1320 is also input to the multiplexer 1340, and the multiplexer 1340 outputs a signal output from the multiplexer 1330, that is, a preamble and the physical data 1320 in FIG. 9. Multiplexed to correspond to the physical layer frame structure as described above to generate and output to the physical layer frame.

13 illustrates the internal structure of the physical layer frame transmitting apparatus, and a process of generating the physical layer frame will now be described with reference to FIG. 14.

FIG. 14 is a flowchart illustrating a process of transmitting a physical layer frame corresponding to FIG. 13.

Referring to FIG. 14, the physical layer frame transmitter as described with reference to FIG. 13 first generates a first preamble for synchronization acquisition in step 1400 and proceeds to step 1420. In operation 1410, the physical layer frame transmitting apparatus generates a second preamble for channel estimation, and proceeds to operation 1420. In operation 1420, the physical layer frame transmission apparatus concatenates the generated first preamble and the second preamble in time and generates them as a preamble. In step 1430, the physical layer frame transmission apparatus multiplexes the generated preamble and physical data according to the physical layer frame structure described with reference to FIG. 9 to generate a physical layer frame, and proceeds to step 1440. In step 1440, the physical layer frame transmitting apparatus transmits the generated physical layer frame over air and ends.

13 and 14, a physical layer frame transmitting apparatus and a transmitting method have been described. Next, a physical layer frame receiving apparatus and a receiving method will be described with reference to FIGS. 15 and 16. FIG.

FIG. 15 is a diagram schematically illustrating an internal structure of a physical layer frame receiving apparatus corresponding to FIG. 13.

Referring to FIG. 15, when the physical layer frame 1500 is first received from the air, the received physical layer frame 1500 is input to a demultiplexer (DEMUX) 1510. The demultiplexer 1510 demultiplexes the physical layer frame 1500 corresponding to the physical layer frame structure described with reference to FIG. 9 to output a preamble to the demultiplexer 1520, and the physical data is a data decompressor 1550. Will output The demultiplexer 1520 demultiplexes the preamble output from the demultiplexer 1510 corresponding to the physical layer frame structure described with reference to FIG. 9, and outputs a first preamble to the correlation checker 1530, and a second preamble. Is output to a channel estimator 1540.

The correlation checker 1530 checks autocorrelation with the first preamble output from the demultiplexer 1520, and determines that synchronization has been obtained when the set correlation is set in advance as a result of the autocorrelation test. The obtained synchronization information 1570 is output to the channel estimator 1540 and the data decompressor 1550. Meanwhile, the channel estimator 1540 estimates the channel with the second preamble output from the demultiplexer 1520 and the synchronization information 1570 output from the correlation checker 1530, and calculates the channel estimation result. Output to data restorer 1550. The data decompressor 1550 has the synchronization information 1570 output from the correlation checker 1530 and the channel estimation information output from the channel estimator 1540 and the physical data output from the demultiplexer 1510. The decoded data is output as the actually restored physical data 1560. Of course, when the correlation is not obtained from the correlation checker 1530, no further operation, that is, channel estimation and physical data restoration, is not performed.

The physical layer frame receiving apparatus has been described with reference to FIG. 15, and a physical layer frame receiving process will now be described with reference to FIG. 16.

FIG. 16 is a flowchart illustrating a process of receiving a physical layer frame corresponding to FIG. 15.

Referring to FIG. 16, if the physical layer frame is received from the air in operation 1600, the physical layer frame receiving apparatus proceeds to operation 1610. In operation 1610, the physical layer frame receiving apparatus demultiplexes the received physical layer frame according to the physical layer frame structure described with reference to FIG. 9 to demultiplex the first preamble, the second preamble, and the physical data. Using the demultiplexed first preamble, the physical layer frame receiving apparatus detects synchronization information by performing a synchronization acquisition process, and then proceeds to step 1640. In operation 1640, the physical layer frame receiving apparatus detects a channel estimation value by performing a channel estimation process by using the demultiplexed second preamble. In step 1640, the physical layer frame receiving apparatus restores the physical data to original data by using the synchronization information and the channel estimation value, and ends.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, the present invention divides a preamble of a physical layer frame into a synchronous acquiring preamble and a channel estimation preamble in an ultra-wideband communication system, and applies aperiodic or cyclic sequences to suit respective characteristics. It has the advantage of increasing the estimated efficiency. In particular, when the ultra-wideband communication system uses the BPSK scheme as a modulation scheme, the CAZAC sequence that is currently used is not suitable for synchronization acquisition. However, an ARM sequence is used for a preamble used for synchronization acquisition and channel estimation is performed. The preamble used has the advantage of increasing the synchronization acquisition and channel estimation efficiency by using the ARM sequence or the CAZAC sequence appropriately for the radio channel situation, thereby improving the overall system performance of the ultra-wideband communication system.

Claims (18)

In the preamble transmission apparatus of an ultra-wideband communication system, A first preamble generator for generating a first preamble, which is a preamble for synchronization acquisition, using an aperiodic sequence having an aperiodic correlation characteristic; A second preamble generator for generating a second preamble that is a preamble for channel estimation using the aperiodic sequence; And a transmitter for multiplexing the first preamble and the second preamble and transmitting the multiplexed preambles to a preamble of the ultra wideband communication system. The method of claim 1, And the aperiodic sequence is an aperiodic recursive multiplex (ARM) sequence. In the preamble transmission apparatus of an ultra-wideband communication system, A first preamble generator for generating a first preamble, which is a preamble for synchronization acquisition, using an aperiodic sequence having an aperiodic correlation characteristic; A second preamble generator for generating a second preamble, which is a preamble for channel estimation, using a periodic sequence having a periodic correlation characteristic; And a transmitter for multiplexing the first preamble and the second preamble and transmitting the multiplexed preambles to a preamble of the ultra wideband communication system. The method of claim 3, And the aperiodic sequence is an aperiodic recursive multiplex (ARM) sequence. The method of claim 3, And the periodic sequence is a constant amplitude zero auto correlation (CAZAC) sequence. In the preamble receiving apparatus of an ultra-wideband communication system, A demultiplexer for demultiplexing a received signal and outputting a first preamble as a synchronization acquisition preamble, a second preamble as a channel estimation preamble, and outputting data; A correlation checker configured to perform synchronization acquisition with the first preamble and to output synchronization information according to the synchronization acquisition result; A channel estimator for performing channel estimation with the second preamble and outputting a channel estimation value according to the channel estimation result; And a data decompressor for restoring the data to the original information data using the synchronization information and the channel estimate value. The method of claim 6, And the first preamble and the second preamble are aperiodic sequences, and the aperiodic sequence is an aperiodic recursive multiplex (ARM) sequence. The method of claim 6, And the first preamble is an aperiodic sequence, and the aperiodic sequence is an aperiodic recursive multiplex (ARM) sequence. The method of claim 6, The second preamble is a periodic sequence, wherein the periodic sequence is a constant amplitude zero auto correlation (CAZAC) sequence, the preamble receiving apparatus of the ultra-wideband communication system. In the preamble transmission method of an ultra-wideband communication system, Generating a first preamble, which is a preamble for synchronization acquisition, using an aperiodic sequence having an aperiodic correlation characteristic, Generating a second preamble, which is a preamble for channel estimation, using the aperiodic sequence; And multiplexing the first preamble and the second preamble to transmit the preamble to the preamble of the ultra wideband communication system. The method of claim 10, And wherein said aperiodic sequence is an aperiodic recursive multiplex (ARM) sequence. In the preamble transmission method of an ultra-wideband communication system, Generating a first preamble, which is a preamble for synchronization acquisition, using an aperiodic sequence having an aperiodic correlation characteristic, Generating a second preamble, which is a preamble for channel estimation, using a periodic sequence having a periodic correlation characteristic; And multiplexing the first preamble and the second preamble to transmit the preamble to the preamble of the ultra wideband communication system. The method of claim 12, And wherein said aperiodic sequence is an aperiodic recursive multiplex (ARM) sequence. The method of claim 12, The periodic sequence is a constant amplitude zero auto correlation (CAZAC) sequence, characterized in that the preamble transmission method of the ultra-wideband communication system. In the preamble receiving method of an ultra-wideband communication system, Demultiplexing a received signal and outputting the first preamble, which is a preamble for synchronization acquisition, and a second preamble, which is a preamble for channel estimation, and outputting data; Performing synchronization acquisition with the first preamble and outputting synchronization information according to the synchronization acquisition result; Performing channel estimation with the second preamble and outputting a channel estimate according to the channel estimation result; And restoring the data to the original information data using the synchronization information and the channel estimate value. The method of claim 15, Wherein the first preamble and the second preamble are aperiodic sequences, and the aperiodic sequences are aperiodic recursive multiplex (ARM) sequences. The method of claim 15, And wherein the first preamble is an aperiodic sequence, and the aperiodic sequence is an aperiodic recursive multiplex (ARM) sequence. The method of claim 15, And wherein the second preamble is a periodic sequence, and the periodic sequence is a constant amplitude zero auto correlation (CAZAC) sequence.